PdxJ is required in the biosynthesis of pyridoxine (vitamin B6), a precursor to the enzyme cofactor pyridoxal phosphate. ECOCYC describes the predicted reaction equation as 1-amino-propan-2-one-3-phosphate + deoxyxylulose-5-phosphate = pyridoxine-5'-phosphate. The product of that reaction is oxidized by PdxH to pyridoxal 5'-phosphate.